Electronic control for toy electric railroads



Dec. 23, 1952 J. L. BONANNO 2,622,542

ELECTRONIC CONTROL FOR TOY ELECTRIC RAILROADS Filed 001;. 11, 1947 3Sheets-Sheet l Paws:

Cone/-20 PECE/VER, Rs: r/r/ER, 8 P51. A Y

INVENTOR JOSEPH L. flown/VH ATTORNEY Dec. 23, 1952 J. L. BONANNOELECTRONIC CONTROL FOR 'roy ELECTRIC RAILROADS Filed Oct. 11, 1947 '3Sheets-Sheet 2 Tlcjn.

' IN V EN TOR. JOSEPH L. Bohmwo 4 7' TORI/EV Dec. 23, 1952 J. L. BONANNO2,622,542

ELECTRONIC CONTROL FOR TOY ELECTRIC RAILROADS Filed 001;. 11, 1947 sSheets-Sheet :s

1 E 29 fl/ ML.

80 "E. N N o BY ATTORN Y Patented Dec. 23, 1952 UNITED STATES PATENTOFFICE ELECTRONIC CONTROL FOR TOY ELECTRIC RAILROADS Application October11, 1947, Serial No. 779,273

Claims. 1

The present invention relates to electronic controls and is moreparticularly directed toward controls for use in toy electric railroads.

Toy electric railroads are operated at comparatively low voltages offrom -8 to 25 volts supplied either through the current reducer fordirect cur-- rent operation or through a transformer for alternatingcurrent operation. Two wires are used from the source of supply to thetrack circuit for providing propulsion current for the locomotive,current for the lights and current for operating train carriedaccessories such as locomotive reversing switches, whistle motors,couplers, car unloading mechanism and the like, as well as track sideaccessories such as lamps and track switches.

Controls for these devices have generally been effected through suchexpedients as the use of superposed rectified current on the alternatingpower supply, the use of specially equipped track sections adapted tocooperate with specially equipped cars, or the use of direct wireconnections, for example, to track switches.

The present invention contemplates an electronic control systemaccording to which the control currents of high or radio frequency aresuperimposed on the propulsion circuit, whether the same be analternating current or a direct currentcircuit. In the latter case carehas to be taken to maintain polarity relations.

According to the present invention the power supply is connected to anelectronic oscillator with tuned circuits of selected frequencies andthe output of the oscillator is impressed upon the lower voltage supplycircuit for the track layout so that the high frequency currentcirculates through the track circuit, there being receivers suitablydisposed in relation to various accesseries and load circuits of thetrain and track layout which are individually pre-tuned to thefrequencies available from the oscillator. This makes it possible tointerconnect the electronic transmitter with the usual track circuit andoperate the train and accessories entirely through electronic controls.The speed of the train is usually controlled by varying the voltagesupplied to the track circuit.

The accompanying drawings show, for purposes of illustrating the presentinvention, an embodiment in which the invention may take form, togetherwith modified wiring diagrams, it being understood that the drawings areillustrative of the invention rather than limiting the same. I

In these drawings,

Figure l is a diagrammatic view illustrating the relation of train,track, track circuit, transformer and electronic controller;

Figure 2 is a wiring diagram illustrating the entire system, theoscillator output coil being in series with the track power supply;

Figure 3 is a wiring diagram for the electronic transmitter, thestructural parts being diagrammatically illustrated;

Figure 4 is a top plan view showing the structure of a controller withparts in section along the line 4-4 of Figure 5;

Figure 5 is a vertical, sectional view on the line 5-5 of Figure 4;

Figure 6? is a section on the line 65 of Figure 5; and

Figures '7 and 8 show modified wiring diagrams in which the oscillatoroutput is in parallel with the transformer, Figure 7 being for an A. C.circuit and Figure 8 for a D. C. circuit.

In Figure 1 a fragment of a toy track layout is shown, the center orpower rail being at Ill and the return or wheel bearing rails at l ll l.The rolling stock as shown includes a locomotive L, tender T and car C.The locomotive has the usual motor l3 and reversing switch 14. Thetender and car are connected together by electromagnetic couplers I5.The tender carries. two receivers l6 and H, the receiver [6 beingadapted to control the reversing switch It While the receiver IIcontrols the motor for the whistle indicated at l8. The car 0 carries areceiver I9 adapted to control the energizing circuit from the coupler15. These receivers are connected to the third rail through rollersindicated at 20.

The propulsion current circuit includes a variable voltage stepdowntransformer 2 I connected to the power supply wires 22 andhaving anoutput circuit whose wires 23 and 24 are connected to terminals 25 and2B of a radio frequency transmitter designated generally by thereference character 21. Where a, D. C. source is employed one uses acurrent reducer such as shown in Figure 8 and connects to the radiofrequency transmitter in the same way as the transformer. This radiofrequency transmitter has an output coil 28 composed of a few turns ofheavy copper wire which in the circuit of Figure 2 is connected inseries between terminal 25 and an output terminal 29. The terminal 26 ofthe controller 21 is connected by a strap 36 to an output terminal 38.The terminals 29 and 30 of the radio frequency transmitter are connectedby wires 3| and 32 with the center and grounded rails respectively ofthe track layout.

The radio frequency transmitter 21 has input terminals 40 and ll adaptedto be connected to the power supply 22 usually through a lamp cord 42 asindicated. The transmitter is here shown as provided with adiode-pentode vacuum tube having two filaments 43 and 44 connectedbetween the terminals 40 and 4|. The filament 43 cooperates with ananode 45 and cathode 46 of a diode section, while the filament 44cooperates with a cathode 41 and anode 48 and two grids 49 and 50respectively of a pentode section. The anode 45 of the diode section isconnected to the filament as indicated at SL The anode 48 of the pentodesection is connected by a wire indicated at 52 with one side of atrimmer condenser 53 and with a metal plate 54 having a plurality ofresilient fingers 55 adapted to be brought into engagement with contacts56 connected to a plurality of taps carried by a tank coil 51. One endof the tank coil 51 is connected to the trimmer condenser 53 by a Wireindicated at 58; while the other end of the tank coil 51 is connectedthrough a radio frequency choke 59 and wire with the cathode 46 of thediode section. 'Iwo condensers SI and 62 are in series with one anotherand in parallel with the trimmer condenser and the three condensers actas an adjustable capacity across the tank coil. These condensers areconnected to the filament circuit by a wire indicated at 03, thecondenser BI is shunted by a condenser 64 and resistance 65 connected tothe control grid 50 by a wire 65. The screen grid 40 is connected to theradio frequency choke lead 00 through a resistance 65 and to the cathode41 and filament circuit through a condenser 01. A condenser 68interconnects the filament 44 and cathode 47 with the choke lead 60. Acondenser 09 is placed across the input terminals 25 and 20 to bypassthe radio frequency currents on the power side.

When the device is designed for operation on 60 cycle house current andemploys a No. lllNlGT or ll'lP'lGT tube, suitable values for thecondensers, resistances, choke and tank coil are as follows:

Condenser 53 10-160 mfd.

Condenser 6I .005 mfd. i

Condenser 62 .002 mfd. 1 5%.

Condenser 64- .001 mfd.

Condenser 5'I .002 mfd. i 10% 150-400 v.

Condenser 00 20-30 mfd. dry electrolytic Condenser 00""- .1 mfd. paper150-400 v'.

Resistance 65 M watt carbon resistor.

Resistance 66... 15M 1 watt carbon resistor.

Tank coil 5'I 165 turns.

Outputcoil 281- 5 turns. Radio frequency 80 ohms 7.5 mh.

choke 59.

With proper location of the taps in the coil it is possible to securefrequencies of from 240 to 360 kilo'cycles to be supplied the propulsioncircuit and a selected frequency in this range is available when thedesired. button is depressed.

Receivers such as 15, I l and IQ, of Figure l, have a wiring diagramsuch as shown in Figure 2. The units include a variable tuning devicehaving coil "I0, condenser 'II and adjustable core 12, a secondary coilIll connected at its ends to w a full wave rectifier E4 and at its midpoint to relay coil I4, as more fully described and claimed in myapplications Serial No. 719,811, filed January 2, 1947, now PatentNumber 2,581,- 165, dated January 1, 1952; Serial Nos. 771,447

4 to 771,449, filed August 30, 1947, now Patent Numbers 2,526,453 to2,526,455, respectively, all dated October 15, 1950.

The structural embodiment of the electronic controller shown in thedrawings is in the form of a comparatively small, totally enclosed unithaving the lamp cord 42 for connection to the power supply and theterminals 25, 20, 29 and 30. The device has a base made of two pieces BIand 82 of sheetmetal welded together, and a yoke or bracket 83 welded tothe base and having upwardly bent ends 84 and 85 slotted as indicated at80 to form bifurcations 81 and 88. The ends of these bifurcations arereduced, pass through holes in an insulating plate 09, and are twistedas indicated at to secure the plate 89 in place.

The plate 89, through insulating posts 9I, supports a tube 92 on whichthe tank coil 51 is wound. One of these posts supports the choke 59. Theoutput coil 28 is secured to the tube and its ends connected to bindingposts 25 and 29.

The plate 89 carries contact pins 55 connected by wires to the coiltaps. It also carries the metal plate 54 with resilient fingers. Thesefingers are operated by push buttons 02 (appropriately colored) held inplace by a retainer plate 93. The trimmer condenser 53 is secure toplate 89 and connected by wire with plate 54.

An 8-contact vacuum tube socket 95 is secured to the base to the rear ofthe coil and push buttons. This socket carries a diOde-ptentode tube 90.The. condensers and resistances are wired in to the structure asindicated in Figure 3. The terminals 25, 25, 29 and 30 are secured. toan insulating plate 9! and all the wiring parts are enclosed by a coverdesignated generally by the reference character 98. This cover has anapertured plate 99 through which the bulb of the vacuum tube extends.The cover is provided with openings I00 for the push buttons and withventilation openings I 0 I Instead of connecting the transformer andoscillator output coil in series as in Figures 2 and 3, they may beconnected in parallel by shifting the transformer secondary connectionfrom the binding post 25 to the binding post 29 as shown by wire I02 inFigure 7. This circuit has also been found satisfactory because of thehigh impedance of the transformer.

Figure 8 illustrates a parallel circuit arrangement for D. C. operationin which the wire I03 connects the grounded side of the current reducerI04 (such as shown in Caruso 1,697,412), and with the track. Theinductively wound reducer connection employed in such current reducershave sufliciently high impedance to block radio frequency currents.

Since it is obvious that the invention may be embodied in other formsand constructions within the scope of the claims, I wish it to beunderstood that the particular form shown is but one of these forms, andvarious modifications and changes being possible, I do not otherwiselimit myself in any way with respect thereto.

What is claimed is:

1. In a toy railroad system operable from the usual house current sourceof power supply,- a track layout including a plurality of insulatedrails for wheel support and current conduction, a voltage reducingdevice connected to one of the rails, a coil of comparatively few turnsand adapted to form an oscillating current output coil and connected tothe other rail and to the voltage reducing device to transfer radiofrequency currents to the same, a radio frequency transmitter connectedto the source of power and having a multitapped oscillator tank coilinductively coupled to the first mentioned coil, a power operatedoscillator supplying current to the tank coil, and connected to normallyopen switches one for each tap of the tank coil, and a train on thetrack having a plurality of electronic receivers each tuned to afrequency corresponding to that transmitted to the track by closing oneof the switches, a normally open-circuit relay connected to one of therails and operable by the receiver, and a low voltage, power operabledevice connected to the other rail and to the relay.

2. A system as claimed in claim 1, wherein the oscillator includes adiode and a pentode.

3. A system as claimed in claim 1, wherein the output coil is in serieswith the voltage reducing device and a track rail.

4. A system as claimed in claim 1, wherein the output coil is inparallel with the voltage reducing device and a track rail, and thevoltage reducing device has radio frequency limiting impedance.

5. In combination, a toy railroad track, a, track carried toy trainhaving a plurality of current consuming devices each connected to one ofthe rails of the track, a plurality of normally open circuit relays eachhaving one side connected to the other rail of the track and to theother side of the corresponding current consuming device,

a tuned electronic receiver operably connected to the coil of each relayand to the rails of the track, means to supply current to the tracks ata voltage substantially below house current voltage, a radio frequencytransmitter with its input at house current voltage and including arectifier, a vacuum tube oscillator, condensers, resistances, a multitaposcillator tank coil, tap selecting switches whereby a selectedfrequency may be generated in the tank coil and an oscillation outputcoil of few turns connected to the tracks to supply them with highfrequency current for actuating a selected receiver and its relay andconnecting the corresponding load to the track.

JOSEPH L. BONANNO.

REFERENCES CITED The following references are of recordin the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,569,233 Morton Jan. 12, 19362,073,443 Cardoza Mar. 9, 1937 2,173,483 King 1 Sept. 19, 1939 2,378,326Rees et al June 12, 1945 2,429,819 Jordan Oct. 28, 1947 2,430,471 LandNov. 11, 1947 FOREIGN PATENTS Number Country Date 820,714 France Nov.17, 1937

